Mechanism for operating electric switches



Sept 2.5., 1928.

... W. BOND MECHANISM FOR OPERATING ELECTRIC SWITCHES s mi Filed Nov.25, 1927 Figa.

Patented Sept. 25, 1928.

UNITED STATES PATENT oFFicE.

LESLIE W. BOND, OF SCHIENECTADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRICCOMPANY, A CORPORATION 0F NEW YORK.

IECHANISM FOB OPERATING ELECTRIC SWITCHES.

Application led November 25, 1827. Serial No. 235,412.

My invention relates to mechanisms for operating electric switches,which are adapted 'for both manual and automatic operation, and moreparticularly for electric switches of large current carrying capacitywherein it is desirable to move the switch to opencircuit position witha minimum amount of energy. My invention lies in a novel arrangement ofparts which constitutes an improvement upon similar devices heretoforeknown in the art.

According to my invention, I providean operating mechanism embodying acompound toggle mechanism for latching the switch to closed circuitposition whereby it is possible for the switch to be quickly moved to'open circuit position by the expenditure of a minimum amount of elort.Provision is also made 'for manually operating the switch to eitherclosed circuit or open circuit position.

The novel features which I believe to be characteristic of m invention'will be definitely indicated in the appended claims while the featuresof construction and mode of operation will be more clearly understood byreference to the following description taken in connection with theaccompanying drawing which shows the preferred embodiments of myinvention.

Referring to the drawing, Figure 1 is a perspective view of a switchembodying my invention, partly cut away, to more clearly illustrate thearrangement of parts; Fig. 2 is a side elevation showing the operatingmechanism in open circuit position; Fig. 3 is aside elevation showingthe operating mechanism in closed circuit position as actuated by theclosing solenoid; Fig. 4 is a side elevation showing the operatingmechanism tripped to open circuit position by means'oi the manuallyoperated trip; Fig. 5 is a similar side elevation showing the operatingmechanism moved into closed circuit position by means of the manuallyoperating means, 'and Fig. 6 is a side elevation of the manual operatingmeans.

Automatic closing of the switch is accom'- plished as follows: Referrintothe drawing, 1 represents a base or Stan ard upon whicli are mountedthe operating mechanism and the stationary contacts-2. Cooperating withthese contacts, are the movable contacts d carried on an operating crank4 comprising a shaft 5 covered with an insulating covering 6, upon whichis rigidly secured the dog 7. r

The shaft 5 is rotatably mounted in suitable pro3ect1ons 8 of the base 1(only one being shown in the drawing).4 The dog 7 is connected to thebase by means of a toggle mochanism comprising the links 9 and V10. Thistoggle mechanism 9-10 is actuated by the links 11, one end of each beingconnected to the toggle by the pin 12 and the other being pivotallyconnected to the plunger 13 of the solenoid 14. The movement of theplunger 13 is so ixed that the pin 12 is always below dead center ot thetoggle mechanism, so that the spring pressure of the contacts willalways tend-to buckle the toggle and open the switch. Energization otthis solenoid lifts the plunger 13 which straightens the toggle 9-10 torotate the crank 4 clockwise and bring the movable contacts 8 intoengagement with the stationary contacts 2.

IThe pin 12 extends beyond the toggle mechanism and engages with a crank15 pivotally mounted on a shaft 16 suitably joui-nailed in projections(not shown) on the base 1. This shaft 16 also serves as a pivot for linky10 ot the toggle mechanism. A compression spring 17 is interposedbetween the crank 15 and the projection 8 ot the base and exerts a'force additive to that ot the spring pres* surepotythe contacts tendingto torce the pin 12 downward, buckling the toggle 9-10 to open theswitch.

Link 9 has a projection 18 carrying a roller 19 (best shown in Figure 2)which engages the surface 20 of the lever 21. This lever 21 is lalsopivoted on the shaft 16 and is biased to move in a clockwise directionby means of the spring 22. The other end oi' lever 21 is connected tothe projections 23 of the base by means of a second toggle mechanismcomprisi ng the links 24-Q5- This toggle 24-25 is connected through alink 26, having a lost i motion slot 27, to the plunger 28 of `thetripping solenoid 29.

The operation ot the latchin mechanism is as follows: When the movab econtacts 3 have been moved to circuit closedlposition as describedabove, the roller 19 on the projection 18 of link 9 rides up the surface20 of iever 21 and allows the biasing spring Q2 to turn the lever 21 ina clockwise direction about the shaft 16. As the upper end of lever 21moves to the right, the toggle 24--25 is straightened and falls slightlypast dead center by its own weight, latching the lever 21 in thisposition. The surface 2O of this lever in turn engages the roller on theprojection 18 of link 9 and preventsthe toggle 9-10 from buckling,whereby the switch is latched in closed position.

After the breaker is latched closed, it is 'desirable that the closingsolenoid should be fle-energized; This de-energization of the closingsolenoid is accomplished by means ot an auxiliary contactor 30 whosecoil circuit is broken when the switch is closed, by means of theinterlock 31, actuated by a pin 32 secured to the lever 21. Thisexpedient is well known in the art and forms no part of this invention.

Energization of the tripping solenoid 29 draws up the plunger 28connected to the link 26 which buckles the toggle 24-25 upward slightlypast dead center. The spring pressure of the contacts, and torqueexerted by spring 17 then turns lever 21 in a counterclockwisedirectionto open the switch and complete the buckling of toggle 24-25, which isaccomplished by its' pivot pinsliding upward in the lost motion slot 27of link 26. This lost motion slot enables the tripping plunger 28 tohave a very limited motion, so that the open circuit air gap of thesolenoid 29 is very small, and a maximum electromagnetic pull isobtained on the plunger 28 for a given energy consumption by thetripping solenoid. l

Provision is made for manually operating the switch at t-he will of theoperator. This manual operating means comprises a handle 33 rigidlysecured to a hub 34 which is pivotally mounted on the shaft 16. Hub 34has a shoulder 35 adapted to engage the crank 15 when the handle 33 isrotated in a clockwise direct-ion, shown in Fig. 6, as position A, and'close the switch.' The operation of the mechanism in closing andlatching is the same as previously described under automatic operation.This is shown in Fig. 5.

The hub 34 also has an ear 36 which is pin connected to the linkmechanism 37-38-39-40-4 1. Upon a movement of the handle 33 to positionB, Fig. 6, the ear 36 is moved in a counterclockwise direction raisingthe link 37 which in turn, through the link 38, turns the links 39-40,which are rigidly secured together, in a counter-'clockwise directionabout the pivot 43. The link 40 is adapted to engage one end oa lever 41pivoted freely on the pin 44. The other end of the lever 41 engages thecenter pin of the auxiliary toggle 24-25, and the counterclockwisemovement of the link 40 causes a clockwise movement ot the lever 41which buckles the toggle 24--25 and allows the Leganes switch mechanismto open as described above in connection with automatic operation. Thelink 37 has a lost motion slot 45 in which moves the pin 46 connected tothe link 38. This allows the switch mechanism to open trip free of thehandle, whereby the opening of the switch is more rapid and morecertain. The corresponding position of the elements is now as shown inFig. 4. The handle 33 is now returned to position C which is the neutralposition maintained for electrical operation and the apparatus is inreadiness toV be closed automatically in response to energization of theclosing solenoid, or manually by moving the operating handle 33 toposition A. i

In accordance with the provisions of the patent statutes I havedescribed the preferred embodiment of my invention, but I do not wish tobe limited to the particular construction shown and described, as itwill be apparent to those skilled in the art that many modificationstherein may be made without departing from the scope of the invention asset forth in the appended claims.

What 1 cla-im as new and desire to secure by Letters Patent of theUnited States, is

1. A switch operating mechanism comprising a base, an operating crankpivotally mounted on said base, a toggle mechanism between said crankand said base biased to open circuit position, a solenoid having aplunger, a1 link connection between said plunger and said toggle foractuating the same, an eXtension on one link of said toggle carrying aroller, a lever pivotally connected to said base and biased to theposition corresponding to closcd circuit, one end of said lever beingadapted to engage said roller and the other end being connected to saidbase through a second toggle mechanism whereby the switch is latched inclosed circuit position, a tripping solenoid having a plunger and a linkconnection between said last mentioned plunger and said second togglemechanism whereby the lever and crank are released to open the switchwhen the tripping solenoid is energized. n 2. In combination, anelectric switch having a stationary contact mounted on a base, acooperating movable contact carried by an operating crank pivota-llymounted on said base, a toggle mechanism between said crank and saidbase biased to open circuit posit-ion, a closing solenoid having a.plunger', a link connection between said plunger and said toggle foractuating said toggle to close the switch, an extension on one link ofsaid toggle carrying a roller, a lever pivotally connectcd to said baseand biased to the position corresponding to closed circuit, one rnd ofsaid lever being adapted to engage said roller and the other endbeingconnectcd to said base through a second toggle mechanism wherebythe switch is mechanically latched in closed circuit position, atripping solenoid having a moved in one direction, and to break saidsecplunger and a link connection between said 0nd toggle through a linkmechanism when l0 last mentioned plunger and said second toggle moved inthe opposite direction, to open the mechanism whereby the lever andcrank are switch.

5 released to open theswitch when the tripping In witness whereof I havehereunto set my solenoid is energized, and manually operable hand this23d day of November, 1927. means pivotall -mounted on said base adaptedto rotate sai crank to close the switch when LESLIE W. BOND. v

